Our knowledge of the functional interaction between retina and retinal pigment epithelium (RPE) is limited, but many ophthalmic disorders involve pathology at the level of the RPE or photoreceptors. Fundus disorders are often localized as either macular disease or peripheal disease, although the reasons for such localization are in general unknown. I propose to study two physiologic processes in which the RPE and photoreceptors interact and may depend upon each other, photopigment regeneration and adhesion. I hope to elucidate the relative contribution of the two layers to each process, and apply this information towards an understanding of regional differences within the eye and clinical disorders. Pigment regeneration will initially be studied in the frog, in which the retina can easily be peeled from the dark adapted eyecup. After bleaching, regeneration will be studied under a variety of experimental conditions in which the retina remains isolated or is replaced upon the RPE. The technique will then be extended to mammals. Adhesion will initially be studied in the rabbit and cat, by gluing probes to the retinal surface and measuring the force required to tear or detach the retina in different regions of the eye during appropriate experimental maneuvers. I hope that both regeneration and adhesion studies can eventually be extended to the primate eye, in which a comparison between the central and peripheral parts of the fundus would have direct relevance for macular and peripheral retinal disorders in the human.